The invention relates to an interlock arrangement for a unitary molded enclosure for electrical terminals, such as for a dead-front electrical plug or connector. More specifically, the invention relates to an interlock arrangement formed of one or more locking members integrally formed with one or more moveable wall portions connected by a web hinge or web hinges to the remainder of the enclosure and interengaging locking members integrally formed with the remainder of the enclosure such that the interengaging locking members engage one another when the enclosure is folded or closed.
There have been some prior art proposals for electrical connector plugs which use web-hinged covers and suggest engagement of mating projections and recesses of the two hinged covers when the connector is assembled. See, for example, British Patent Specification No. 676144, published in 1952 and French Pat. No. 1394871, published in 1965. Other types of interengaging projections and recesses are suggested in U.S. Pat. Nos. Des.201,442; 3,576,518; 3,836,944; 3,856,376; 3,899,236 and 3,971,616.
An improved interlock arrangement is provided in accordance with this invention. In one embodiment the interlock arrangement is for a unitary molded enclosure for electrical terminals. The enclosure has at least one moveable wall portion joined by a web hinge to the remainder of the enclosure. The enclosure is made of an electrically insulating material and has an interior chamber for housing the electrical terminals. The web hinge joins one edge of the moveable wall portion to an adjoining surface of the enclosure to permit pivotal movement of the moveable wall portion on the web hinge to an open position which provides access to the interior chamber of the enclosure. There are locking means for releasably interlocking the moveable wall portion to the enclosure when the moveable wall portion is in a closed position, so as to relieve stress on the web hinge and to lock the wall portion against displacement both outwardly away from the enclosure and transverse to said outward direction. The locking means includes a number of interengaging locking members adjacent the web hinge, at least one being integral with the moveable wall portion and at least one being integral with an adjacent portion of the enclosure. These interengaging locking members engage one another at a location inwardly of the web hinge when the moveable wall portion is closed.
In another embodiment of the invention, the interlock arrangement is for a unitary molded enclosure for electrical terminals which has a number of integral web hinges each joining one edge of a respective moveable wall portion to an adjoining surface of the enclosure to permit pivotal movement of the respective moveable wall portion on its web hinge to an open position which provides access to the interior of the enclosure. There are locking means for each such moveable wall portion for releasably interlocking the moveable wall portion to the enclosure when it is in a closed position so as to relieve stress on the respective web hinge and to lock the wall portion in the area of the web hinge against displacement both outwardly away from the enclosure and transversely to said outward direction.
The invention provides an interlock arrangement for a unitary molded enclosure for electrical terminals which is particularly inexpensive to manufacture and particularly convenient to assemble and safe to use.